Sometimes I think that the server senses that it is being driven by a robot and "shuts down" or at least severely throttles the responses it delivers?

What about that?

Thanks

That is a very good question BGates.

The only way we know of for a server to detect that you are a robot -- that is, that you are using an automated tool -- is to measure the speed at which you deliver requests, or more generally, to ask you to solve a CAPTCHA.

(Solving a CAPTCHA is a different matter!)

The main issue is best resolved by understanding the relationship between the server and the client (the browser).

The client (that is, YOU) makes requests to the server when it has completed internal processing of the string.

eValid is seen by the server to be a real user because it reports itself as a particular kind of browser.

If you allow normal wait times there should be no problem; you won't be detected as a robot.

But if you set the wait time multiplier to 0.0 so that all requests go very fast, then the speed detection algorithms on the server may (but not always) trap you as a robot and block the request.